LIDAR and the EnvironmentIn
1997 coastal scientists from the Bureau and Center for Space Research
began experimenting with new airborne laser altimetry technology called
LIDAR (Light Detection And Ranging). This technology
enables the collection of high-precision data from an airplane to
produce digital topographic maps called DEMs (Digital Elevation Models).
It is a unique tool for investigating a broad range of scientific
and engineering research problems: shoreline change and wetlands loss;
surface hydrology and flooding; earth surface dynamics and landslides;
forest structure and ecology; and city planning and urban infrastructure
mapping. The Bureaus use of LIDAR includes the mapping of active
geologic environments, such as the Texas coast, where shoreline change
is an important issue. Bureau scientists involved in LIDAR studies
include John
R. Andrews, Jerome
A. Bellian, Edward
W. Collins, James
C. Gibeaut, Roberto Gutierrez, Tiffany
L. Hepner, and Rebecca
C. Smyth.

Using
LIDAR in Honduras: Hurricane Mitch

Soon after the
Bureau purchased its own LIDAR unit in 2000, the U.S.
Geological Survey(USGS) asked the Bureau to participate
in an investigation of the impacts of Hurricane Mitch, which struck
Central America in November 1998. Honduras was especially hard-hit,
and flooding, high winds, and landslides destroyed much of the countrys
infrastructure. Honduras is currently rebuilding the housing and
infrastructure destroyed by the hurricane. To minimize the effects
of future storm disasters, the Honduran government needs maps that
clearly define areas prone to flooding and landslides.

The joint Bureau-USGS
team surveyed 15 municipal areas of Honduras. Maps and surveys that
would have been nearly impossible using ground-based methods were
accomplished in a few weeks. Although the data are currently being
processed, initial results have exceeded expectations. The Bureau
feels proud to be playing a small, but critical, role in helping
Honduras recover from one of the worst natural disasters in Latin
American history.

Municipalities
under study by the USGS The Bureau conducted airborne LIDAR surveys
in those areas slated for flood-risk mapping.

Shaded-relief
topographic image of a portion of the Tegucigalpa Digital Elevation
Model (DEM).

Mayan RuinsIn addition to flood hazard mapping, and when the field
schedule allowed, Bureau scientists made side trips to Copan to
conduct LIDAR and GPS surveys of the Mayan ruins. These LIDAR and
GPS data are being used by archeologists to develop a GIS database,
a crucial element in the Hondurans preservation strategy for
this renowned archeological treasure.

Left
is a shaded-relief topographic image of the Copan Ruins. The image
is from a digital elevation model constructed using only those
LIDAR points that penetrated the vegetation canopy. Right is a
plan of the Mayan structures derived from a ground survey conducted
by Harvard University.